fix(@angular-devkit/build-angular): absolute outputPath outputs index.html in wrong location

Fixes #14474

Author: Alan

packages/angular_devkit/build_angular/src/browser/index.ts

@@ -223,7 +223,7 @@ export function buildWebpackBrowser(
 
             return writeIndexHtml({
               host,
-              outputPath: join(root, options.outputPath),
+              outputPath: resolve(root, normalize(options.outputPath)),
               indexPath: join(root, options.index),
               ES5BuildFiles,
               ES2015BuildFiles,

packages/angular_devkit/build_angular/test/browser/output-path_spec_large.ts

@@ -7,8 +7,8 @@
  */
 
 import { Architect } from '@angular-devkit/architect';
-import { join, virtualFs } from '@angular-devkit/core';
-import { createArchitect, host } from '../utils';
+import { getSystemPath, join, virtualFs } from '@angular-devkit/core';
+import { browserBuild, createArchitect, host } from '../utils';
 
 
 describe('Browser Builder output path', () => {
@@ -48,4 +48,13 @@ describe('Browser Builder output path', () => {
     } catch {}
     await run.stop();
   });
+
+  it('works with absolute outputPath', async () => {
+    const overrides = {
+      outputPath: getSystemPath(join(host.root(), 'dist')),
+    };
+    const { files } = await browserBuild(architect, host, target, overrides);
+    expect('main.js' in files).toBe(true);
+    expect('index.html' in files).toBe(true);
+  });
 });